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451.
130:183954
Bleaching softwood kraft pulp: the role of certain common chemical
elements in the chlorine dioxide stage.
Dahl, O.; Niinimaki, J.; Fiskari, J.; Rasanen, E. (University of Oulu, Oulu
90570, Finland). Pulping Conf., Volume 3, 1177-1183. TAPPI Press:
Atlanta, Ga. (English) 1998. CODEN: 67EEAL. DOCUMENT TYPE:
Conference CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood
Products)
The effects of Mg, K, Ca, and silicate ions on pulp quality and reagent
consumption in the D1 stage of the ECF bleaching process were
investigated on a lab. scale using batch cooked and O-delignified
softwood kraft pulp. Tests were performed by increasing the concns. of
the given ions step by step at the ClO2 stage. The results indicated that
addn. of Mg ions (>1 kg/ODt) decreased clearly viscosity loss of the
pulp in the ClO2 stage. An effect similar to that, although much slighter,
was obsd. when K ions were added, whereas Ca and silicate ions
behaved like inert material in relation to viscosity decrease of the pulp.
No real detrimental effect on brightness, reagent consumption, or the
final tech. properties of pulp were obsd. with an increasing tested ions
concn. in the ClO2 stage.
452.
130:182177
Selective oxidation of dialkyl sulfides to dialkyl sulfoxides by chlorine
dioxide.
Kuchin, A. V.; Rubtsova, S. A.; Karmanova, L. P.; Subbotina, S. N.;
Loginova, I. V. (Institute Chemistry Komi Research Center, Ural Branch
Russian Academy Sciences, Syktyvkar 167610, Russia). Russ. Chem.
Bull., 47(10), 2051-2052 (English) 1998 Consultants Bureau. CODEN:
RCBUEY. ISSN: 1066-5285. DOCUMENT TYPE: Journal CA
Section: 23 (Aliphatic Compounds)
Di-Pr and dioctyl sulfide were oxidized by aq. ClO2 or by a ClO2-air
mixt. in CH2Cl2 to give the sulfoxides in *90% yield.
453.
130:172654
Control of microbial contaminants and disinfection byproducts for
drinking water in the US: cost and performance.
Clark, R. M.; Adams, J. Q.; Sethi, V.; Sivaganesan, M. (Water Supply
and Water Resources Division, NRMRL, US Environmental Protection
Agency, Cincinnati, OH 45268, USA). Aqua (Oxford), 47(6), 255-265
(English) 1998 Blackwell Science Ltd. CODEN: AQUAAA. ISSN:
0003-7214. DOCUMENT TYPE: Journal CA Section: 61 (Water)
The US EPA is in the process of developing a sophisticated regulatory
strategy in an attempt to balance the risks assocd. with disinfectants
and disinfection byproducts (D/DBP) in drinking water. A major aspect
of this strategy is the appropriate application of disinfectants and other
treatment technologies to minimize the formation of DBPs. This paper
explores the cost and performance assocd. with these technol. choices.
The least expensive choice for controlling chlorinated byproducts
would be to utilize an alternative disinfectant. However, precursor
removal by enhanced coagulation and/or the application of granular
activated C and membrane technol. are very effective in controlling
DBPs. The removal of precursors can have the effect of simultaneously
controlling both chem. and microbiol. risks.
454.
130:172650
National Primary Drinking Water Regulations: disinfectants and
disinfectants byproducts.
(Environmental Protection Agency (EPA), USA). Fed. Regist.,
63(241), 69390-69476, (English) 16 Dec 1998 Superintendent of
Documents. CODEN: FEREAC. ISSN: 0097-6326. DOCUMENT
TYPE: Journal CA Section: 61 (Water)
EPA is finalizing max. residual disinfectant levels goals (MRDLGs) for
Cl, chloramines, and ClO2, max. contaminant level goals (MCLGs) for 4
trihalomethanes (chloroform, bromodichloromethane,
dibromochloromethane, dibromochloromethane, and bromoform), 2
haloacetic acids (dichloroacetic acid and trichloroacetic acid),
bromate, and chlorite; and National Primary Drinking Water
Regulations (NPDWRs) for 3 disinfectants (Cl, chloramines, and ClO2),
2 groups of org. disinfection byproducts (total trihalomethanes , sum of
the 4 listed above, and haloacetic acids, sum of the 2 listed above plus
monochloroacetic acid and mono- and dibromoacetic acids), and 2
inorg. disinfection byproducts (chloride and bromate). The NPDWRs
consist of max. residual disinfectant levels (MRDLs) or document
includes the best available technologies (BATs) upon which the MRDLs
and MCLs are based. The set of regulations promulgated today is also
known as the Stage 1 Disinfection Byproducts Rules (DBPR). EPA
believes the implementation of the Stage 1 DBPR will reduced the
levels of disinfectants and disinfection byproducts in drinking water
supplies. The Agency believes the rule will provide public health
protection for an addnl. 20 million households that were not previously
covered by drinking water rule for disinfection byproducts. The rule will
for the 1st time provide public health protection from exposure to
haloacetic acids, chlorite (a major ClO2 byproduct) and bromate (a
major ozone byproduct). The Stage 12 DBPR applies to public water
systems that are community water systems and nontransient
noncommunity water systems that treat their water with a chem.
disinfectant for either primary or residual treatment. In addn., certain
requirements for ClO2 apply to transient noncommunity water systems.
455.
130:169715
Effects of pulping conditions on the bleachability of hardwood kraft
pulps: 1. Effects of effective alkali charge in the pulping of birch and
maple.
Rawat, Nidhi; McDonough, Thomas J. (Institute of Paper Science and
Technology, Atlanta, GA 30318, USA). Pulping Conf., Volume 2,
883-891. TAPPI Press: Atlanta, Ga. (English) 1998. CODEN:
67EEAL. DOCUMENT TYPE: Conference CA Section: 43 (Cellulose,
Lignin, Paper, and Other Wood Products)
The objective of this work was to study the effects of digester alkali
charge on the chlorine dioxide bleachability of hardwood kraft pulps.
We prepd. birch and maple pulps with unbleached kappa nos. in the
19-20 range at two effective alkali (EA) levels, 14% and 20% (Na2O).
These were bleached in the Do(EO)DiED2 sequence. A kappa factor
of 0.2 was used throughout and various combinations of ClO2 charges
in D1 and D2 stages were investigated. The response to ClO2 in the D1
and D2 stages was characterized in terms of the values of the
parameters in a simple math. model, which were then subjected to
statistical anal. The result was a model that describes and predicts the
effect of EA on ECF bleachability. In the case of birch, increasing EA
gave an unbleached pulp of higher brightness, lower total yield, higher
rejects and lower viscosity. The high-EA maple pulp, on the other hand,
had much higher brightness than its low-EA counterpart but similar
yield, rejects and viscosity levels. Increasing EA substantially
increased the brightness ceiling of both the hardwood species. After
the D1 stage, the brightnesses of both high-EA pulps were about 5
points higher than those of their low-EA counterparts and the brightness
advantage of maple over birch was maintained. It was possible to
prep. pulps of 93% ISO brightness in three stages from high-EA maple
pulp. After the 5-stage sequence, the high- and low- EA pulps
exhibited brightness ceilings of 94% ISO and 92% ISO, resp. The
corresponding birch pulps had brightness ceilings close to 90% ISO,
and brightnesses near the ceiling were reached with lower
consumption of ClO2 in the case of high-EA pulp. At moderate levels of
ClO2 consumption, increasing EA allowed substantially higher
brightness to be reached after three stages of bleaching in the case of
maple, and after five stages in case of birch. Much of the beneficial
effect of increasing EA can be attributed to an unbleached pulp
brightness advantage that was retained through the bleaching
sequence, except in the case of five-stage bleaching of birch with high
ClO2 charges.
456.
130:169697
Limits of oxygen delignification.
Chirat, Christine; Lachenal, Dominique (Centre Technique du Papier,
Grenoble 38044, Fr.). Pulping Conf., Volume 2, 619-624. TAPPI
Press: Atlanta, Ga. (English) 1998. CODEN: 67EEAL. DOCUMENT
TYPE: Conference CA Section: 43 (Cellulose, Lignin, Paper, and Other
Wood Products)
Several softwood and hardwood kraft pulps were delignified by
multi-stage O bleaching. In all cases delignification almost stopped
after 3 successive O stages. which corresponded to ~75% and ~60%
delignification for the softwood and hardwood pulps, resp. The
remaining lignin was attached to carbohydrates by linkages which
resisted O bleaching, but not ClO2 bleaching (D). Sequences
combining O and D stages, e.g. ODOD, were proposed. Attractive
results were obtained when D was performed at high temp. for a short
time and washing was omitted between D and O. AOX as low as 0.2
kg/ton of pulp were measured.
457.
130:165436
Bactericidal disinfectant.
Ye, Zhongliang (Peop. Rep. China ). Faming Zhuanli Shenqing
Gongkai Shuomingshu CN 1122189 A 15 May 1996,7 pp. (Chinese).
(People's Republic of China). CODEN: CNXXEV. CLASS: ICM:
A01N059-00. ICS: A61L002-16. APPLICATION: CN 95-108346 29
Jun 1995. DOCUMENT TYPE: Patent CA Section: 10 (Microbial,
Algal, and Fungal Biochemistry)
Bactericidal disinfectant with sp. surface area 100-200 m2/g and
montmorillonite as carrier is composed of two components with the wt.
ratio of 1.5:1-4. One component consists of NaClO, stabilizer, complex
anti- corrosive agent with the wt. ratio of 1:0.01-0.4:0.01-0.5. The
stabilizer is selected from borax or Na2CO3, and the complex
anti-corrosive agent is Na gluconate or Na benzoate. The other
component consists of org. acid and inorg. salt with the wt. ratio of
1:0.1-3. The org. acid is composed of single or mixt. of citric acid,
tartaric acid, and malic acid, and the inorg. salt is composed of single
or mixt. of NaHSO4, KHSO4, Na2S2O7, K2S2O7 and (NH4)2S2O8. The
wt. ratio of NaClO, stabilizer, acidifying agent, and carrier is
1:0.05-0.5:0.05-2:0.5-8.
458.
130:159728
Electrochemical reduction of nitrate.
Kaczur, Jerry J. (Chlor Alkali Products Division Charleston Technology
Center, Olin Corporation, Charleston, TN 37310, USA). Clean Effic.
Process.: Electrochem. Technol. Synth., Sep., Recycle, Environ.
Improv., Int. Forum, Electrolysis Chem. Ind., 12th, 391-417.
Electrosynthesis: Lancaster, N. Y. (English) 1998. CODEN: 67CAAX.
DOCUMENT TYPE: Conference; General Review CA Section: 72
(Electrochemistry) Section cross-reference(s): 60, 61, 78
A review with 25 refs. concerning electrochem. redn. of nitrate and
drinking water purifn. is presented. Olin has developed an
electrochem. redn. technol. that provides an ecol. method of treating
aq. streams contg. oxyhalide and/or oxynitrogen chem. species with the
co-prodn. of little or no hazardous effluent waste.(1-3). This electrochem.
technol., named ElectroRedn., can efficiently reduce various
oxychlorine DBP's (Disinfection Byproducts) species, such as chlorite
(ClO2-) and chlorine dioxide (ClO2), formed from chlorine dioxide
treatment of drinking water to environmentally safe chloride (Cl-)ions.
The redn. technol. can also be used to reduce oxynitrogen species
present in water, such as nitrates (NO3-) and nitrites (NO2-), reducing
them to nitrogen using suitable cathode materials. The ElectroRedn.
process utilizes a high surface area cathode structure design to obtain
high oxy-specie removal efficiencies in single or multiple passes
through the electrolytic system. The selection of cathode materials for
the process is important in maximizing the redn. of the specific
oxychlorine and oxynitrogen anion species present in water while
achieving high operating electrolytic current efficiencies. Bench scale
testing of the redn. process has been demonstrated for the redn. of
chlorite, chlorate, hypochlorite, and nitrate anions. The technol. may be
useful in point-of-use systems or for municipal drinking water treatment.
Applying this technol. for treating large quantities of water, such as in
municipal water systems, will require further engineering design and
scale-up. The redn. process can be applied to the treatment of dil. or
concd. chem. process waste streams. Information on oxynitrogen redn.
chem. as well as bench scale performance data in treating aq. solns.
contg. nitrate as an oxynitrogen specie example is detailed in this
paper.
459.
130:158300
Stable chlorine dioxide disinfectant.
Chen, Xiaoquan; Li, Yanru; Xu, Weichang (Department of Chemical
Engineering, Central South Institute of Technology, Hengyang 421001,
Peop. Rep. China). Xiandai Huagong, 18(9), 41-43 (Chinese) 1998
Zhongguo Huagong Xinxi Zhongxin. CODEN: HTKUDJ. ISSN:
0253-4320. DOCUMENT TYPE: Journal; General Review CA Section:
63 (Pharmaceuticals) Section cross-reference(s): 1
A review with no refs. The stable chlorine dioxide disinfectant with ref.
to the prodn. technol. of chlorine dioxide, stabilization of chlorine
dioxide and its characteristics, and applications of chlorine dioxide ate
discussed.
460.
130:157681
ClO2 and its application to water treatment.
Song, Hong; Xi, Danli (Dept. Environ. Science Engineering, China
Textile University, Shanghai 200051, Peop. Rep. China). Wuran
Fangzhi Jishu, 11(3), 147-150 (Chinese) 1998 Wuran Fangzhi Jishu
Bianjibu. CODEN: WFJIFD. ISSN: 1004-695X. DOCUMENT TYPE:
Journal; General Review CA Section: 60 (Waste Treatment and
Disposal) Section cross-reference(s): 61
A review with 5 refs. on ClO2 technologies. The ClO2 oxidn. power is
stronger than that of Cl2 or NaClO. Meanwhile, it will not produce THM,
chloro-maine and chlorophenol. ClO2 is a green color disinfectant.
This article introduced ClO2 technologies, their mechanism and
applications in water and wastewater treatment.
461.
130:155702
Influence of H2O2 on chloride-dependent reaction path to chlorine
dioxide.
Crump, Brian; Ernst, William R.; Neumann, H. M. (School of Chemical
Engineering, Georgia Institute of Technology, Atlanta, GA 30332,
USA). AIChE J., 44(11), 2494-2500 (English) 1998 American Institute
of Chemical Engineers. CODEN: AICEAC. ISSN: 0001-1541.
DOCUMENT TYPE: Journal CA Section: 49 (Industrial Inorganic
Chemicals)
Reaction paths governing chlorine dioxide formation from solns. of
sodium chlorate, sulfuric acid, hydrogen peroxide, and sodium chloride
at 25* were examd. Chlorine dioxide was formed by two paths: the
redn. of chlorate by hydrogen peroxide and the redn. of chlorate by
chloride. At conditions of this study, the rate of the chloride-chlorate
path predominated and was enhanced by hydrogen peroxide, reaching
an upper limit as hydrogen peroxide concn. was increased. A
mechanism was proposed that explains the obsd. behavior. It is based
on existing theory, but includes a new step: the rapid reaction of
hydrogen peroxide with an intermediate, Cl2O2. It was also shown that
chloride was not required to sustain chlorine dioxide formation in the
hydrogen peroxide-chlorate path.
462.
130:155169
High temperature chlorine dioxide delignification: a breakthrough in
ECF bleaching of hardwood kraft pulps.
Lachenal, Dominique; Chirat, Christine (Ecole Francaise de Papeterie,
Saint Martin d'Heres 38402, Fr.). Pulping Conf., Volume 2, 601-604.
TAPPI Press: Atlanta, Ga. (English) 1998. CODEN: 67EEAL.
DOCUMENT TYPE: Conference CA Section: 43 (Cellulose, Lignin,
Paper, and Other Wood Products)
High-temp. (95*) ClO2 delignification was shown to be more efficient
than a conventional D stage performed at lower temp. (45*). With
hardwood kraft pulp., 20-30% ClO2 could be saved at the same DE
kappa no., provided that the time in D was long enough (1.5-4 h). This
was the effect of the acid medium, which at 95* degraded the
hexenuronic acids and also affected the lignin structure. This was
confirmed by the fact that an AD sequential treatment, where a hot acid
stage preceded a conventional D stage, gave a similar result. Another
way to achieve the same improvement was to raise the temp. to
90-100* at the exit of the conventional D stage and to maintain it for
several hours.
463.
130:155157
Kinetics of chlorine dioxide delignification of eucalypt kraft pulps.
Chandranupap, Panitnad; Nguyen, K. Loi (Australian Pulp and Paper
Institute Department of Chemical Engineering, Monash University,
Clayton, Victoria 3168, Australia). Pulping Conf., Volume 1, 365-373.
TAPPI Press: Atlanta, Ga. (English) 1998. CODEN: 67EEAL.
DOCUMENT TYPE: Conference CA Section: 43 (Cellulose, Lignin,
Paper, and Other Wood Products)
A Nuclei Growth model, developed to describe the kinetics of O
delignification, was used to characterize the kinetics of ClO2
delignification of kraft pulps. The model described the delignification
rate as a function of the reactive site d. in residual lignin (I) and the
expansion rate of the reacted or transformed I initiated at the reactive
sites in the fiber wall. The expansion of the transformed I was assumed
to follow a power law with respect to the reaction time. The model
included the effect of mutual interference between the transformed
zones on the reactivity of I. The model parameters were detd., and its
validity was tested using exptl. results from previous publications and
from bleaching tests with 2o eucalyptus kraft pulps. The model was
robust and can characterize the kinetics of ClO2 delignification with a
high degree of accuracy.
464.
130:147885
Integration of the variogram using spline functions for sampling error
estimation.
Heikka, Riitta; Minkkinen, Pentti (Lappeenranta University of
Technology, Lappeenranta FIN-53851, Finland). Chemom. Intell. Lab.
Syst., 44(1,2), 205-211 (English) 1998 Elsevier Science B.V. CODEN:
CILSEN. ISSN: 0169-7439. DOCUMENT TYPE: Journal CA Section:
79 (Inorganic Analytical Chemistry) Section cross-reference(s): 43
The component of the sampling error caused by taking discrete
samples from a continuous process is the integration error, IE. This
error can be estd. using P.M. Gy's variog. technique. This method
involves the integration of the variogram. The variogram can be calcd.
from a time series of discrete samples. If the variogram is simple, it
can be modeled and integrated. This method was generally used in,
for example, geostatistics. Gy has pointed out that chem. processes
often have variograms that are too complicated to be modeled with
simple equations and has, therefore, proposed a numerical
point-by-point integration method for the exptl. variogram. Although this
method is reliable, it underestimates the integration error for systematic
sampling if a sampling interval close to that used in the variog. expt. is
used. The integration of the variogram is carried out using a cubic
smoothing spline function. The integration errors calcd. with Gy's
method and with the cubic smoothing spline function are compared with
the best est. of the integration error for the simulated data. The
integration errors calcd. from the bleaching process with the
aforementioned methods are also compared. On av., the integration
error calcd. with this new method corresponds better with the best est.
of the integration error than that calcd. by Gy's method for the few 1st
multiples of the sampling interval used in the variog. expt. The
difference between the methods is not significant with longer sampling
intervals, say, five times the interval of the variog. expt. or longer.
465.
130:144399
Electron scattering in ozone and chlorine dioxide.
Gulley, R. J.; Field, T. A.; Steer, W. A.; Mason, N. J.; Lunt, S. L.; Ziesel,
J.-P.; Field, D. (School of Chemistry, University of Bristol, Bristol BS8
1TS, UK). J. Phys. B: At., Mol. Opt. Phys., 31(23), 5197-5208 (English)
1998 Institute of Physics Publishing. CODEN: JPAPEH. ISSN:
0953-4075. DOCUMENT TYPE: Journal CA Section: 65 (General
Physical Chemistry)
Total cross sections are reported for the scattering of electrons by
ozone (O3) and chlorine dioxide (OClO) for energies in the range of 9
meV to 10 eV. The measurements were made in transmission expts.
using synchrotron radiation photoionization app. with an energy resoln.
in the incident electron beam of ~3.5 meV (FWHM). The abs. accuracy
of the cross sections is limited both by exptl. difficulties with respect to
strong rotationally inelastic forward scattering, due to the dipolar nature
of the target mols., and by the compn. of the target gases, which may
depart significantly from pure O3 or OClO. Very marked structure
peaking at 50-60 meV in the spectrum of OClO, and a weak feature at
a similar energy in O3, may represent dissociative attachment. With
respect to rotationally inelastic scattering, for O3, we find that the first
Born pure dipole approxn. is adequate down to energies of 50-60 meV
but fails at lower energies, very markedly overestimating scattering
cross-sections between 10 and 50 meV. In OClO, the Born approxn.
fails seriously, even at energies as high as 1-1.5 eV.
466.
130:140719
Ozone bleaching method of intermediate concentration pulp.
Kitatani, Junji (Mitsubishi Paper Mills, Ltd., Japan). Jpn. Kokai Tokkyo
Koho JP 11021778 A2 26 Jan 1999 Heisei, 5 pp. (Japanese).
(Japan). CODEN: JKXXAF. CLASS: ICM: D21C009-153.
APPLICATION: JP 97-182238 8 Jul 1997. DOCUMENT TYPE: Patent
CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood Products)
The method, for effectively utilization of unreacted ozone exhausted gas
in a pulp manufg. process, is carried out by increasing a 2nd ozone (Z)
bleaching section in replacing of chlorine dioxide (D) stage bleaching
process with Z/D stage process.
467.
130:140681
Loss of volatile organics from kraft bleaching filtrates in
evaporation/drying phase of analysis for dissolved total solids (DTS)
and dissolved volatile solids (DVS).
Luonsi, A.; Lehtonen, M.; Deleuze, S.; Ponni, S.; Halttunen, S.
(Pirkanmaa Regional Environment Centre, Tampere FIN-33101,
Finland). Water Sci. Technol., 38(4-5), 281-288 (English) 1998
Elsevier Science Ltd. CODEN: WSTED4. ISSN: 0273-1223.
DOCUMENT TYPE: Journal CA Section: 43 (Cellulose, Lignin, Paper,
and Other Wood Products)
Measurement for describing dissolved org. matter (DOM) was needed
to calibrate a bleached kraft process model. Volatile solids (VS)
measurement from filtered sample (DVS) was chosen as closest
possible, esp. because it is readily available and easy to perform.
However, the extreme conditions of kraft ClO2 bleaching filtrates, e.g.
pH 2-11, however, demand prerequisite evaluation of the analyzing
method in these circumstances. Measurements before and after
evapn./drying (SFS 3008) and re-dissoln. showed that considerable
amts. of dissolved org. C (DOC) escaped from acid filtrates. When
identified, particularly alcs. and carboxylic acids, but also aldehydes
and ketones, covered the majority of the disappeared quantity.
According to DOC the escaped share was from 17 to 37% in the acid
filtrates, depending on stage (D0/D1/D2) and conditions in prodn.
process. In alk. bleaching stage filtrates, the share was 4 to 9%. The
major identified volatilized compds. in D0-filtrate were MeOH and
HCOOH. They represented 94% of the identified compds. Identified
volatilized quantity from D0-filtrate in DVS measurement represents
about 4-5 kg per metric air-dry ton of pulp as discharge. The C of the
identified volatilized compds. covered 63% of the loss measured as
DOC. Knowledge of volatiles and process conditions is required when
DVS is used for DOM description in kraft bleaching filtrates.
468.
130:129689
Method for manufacturing chlorine dioxide disinfectant used in water
purification device.
Nishimoto, Kiyoshi (Lucky Sun K. K., Japan). Jpn. Kokai Tokkyo Koho
JP 11010164 A2 19 Jan 1999 Heisei, 7 pp. (Japanese). (Japan).
CODEN: JKXXAF. CLASS: ICM: C02F001-50. ICS: C02F001-50;
B01F001-00. APPLICATION: JP 97-205160 25 Jun 1997.
DOCUMENT TYPE: Patent CA Section: 61 (Water)
The method is carried out by passing the water through a horizontal
pipe via a flow-variable valve, arranging a vertical pipe underneath the
horizontal pipe with an opening connected to the horizontal pipe,
introducing aq. soln. of sodium hypochlorite and hydrochloric acid into
the vertical pipe for reaction to generate chlorine dioxide gas for gas
lifting the reaction liq. into the horizontal pipe, dissolving the chlorine
dioxide into the water in the horizontal pipe via a static mixer for water
disinfection.
469.
130:122034
Examination of germicidal efficacy of compound disinfectant of chlorine
dioxide.
Li, Fengling; Peng, Guoke; Ci, Jiuzheng; Bao, Weihua; Qiao, Hong
(Beijing Municipal Sanitary and Anti- epidemic Station, Beijing 100013,
Peop. Rep. China). Zhongguo Xiaoduxue Zazhi, 15(3), 162-164
(Chinese) 1998 Zhongguo Xiaoduxue Zazhi Bianjibu. CODEN:
ZXZAFO. ISSN: 1001-7658. DOCUMENT TYPE: Journal CA Section:
10 (Microbial, Algal, and Fungal Biochemistry) Section
cross-reference(s): 63
The germicidal efficacy of compd. disinfectant of chlorine dioxide was
obsd. The killing rate of Escherichia coli and Staphylococcus aureus in
suspension exposed to a soln. contg. 0.1 mg L- 1 chlorine dioxide and
59 mg L-1 available chlorine for 20 min and the spores of Bacillus
subtilis var. niger exposed to a soln. contg. 0.5 mg L-1 chlorine dioxide
and 296 mg L- 1 available chlorine for 20 min was up to 100%.
470.
130:115613
The kinetics and mechanism of ClO3- formation following the
electrolysis of salt brine: what role do ClO2 and/or O3 play?.
Gordon, Gilbert; Gauw, Renee; Emmert, Gary; Bubnis, Bernard
(Department of Chemistry and Biochemistry, Miami University, Oxford,
OH, USA). ACH - Models Chem., 135(5), 799-809 (English) 1998
Akademiai Kiado. CODEN: ACMCEI. ISSN: 1217-8969.
DOCUMENT TYPE: Journal CA Section: 67 (Catalysis, Reaction
Kinetics, and Inorganic Reaction Mechanisms) Section
cross-reference(s): 61, 72
Chem. kinetics are a key component for understanding the interactions
of species and the establishment of realistic chem. models. In
complicated chem. systems, stoichiometry and kinetic implications
help to clarify data that might otherwise lead to incorrect conclusions.
For example, numerous literature reports cite the presence of multiple
oxidants (HOCl, Cl2, H2O2, chlorine free radicals, O3, and ClO2) in salt
brine solns. that have undergone electrolysis. The presence (or
absence) of inorg. species provides a starting point for detg. which
oxidant species might be present. If chlorine dioxide is present,
chlorite ion formation can be expected. If ozone is present, bromide
ion will undoubtedly react with ozone to produce bromate ion. Anal.
methods capable of selectively measuring various oxidants and their
byproducts have been developed for use in the presence of 300 to 400
mg/l free available chlorine. These methods were used to correlate
reaction stoichiometries and kinetics with field data for electrolyzed salt
brine solns.
471.
130:114704
Purification of drinking water with phenol using activated
carbon-chlorine dioxide method.
Jiang, Boquan; Sun, Risheng; Xie, Fuxiu; Huang, Wenying; Li, Yiyun;
Chen, Yong (Chemical Engineering Department, Nanchang University
330029, Peop. Rep. China). Shuichuli Jishu, 24(6), 336-339 (Chinese)
1998 Shuichuli Jishu Bianji Weiyuanhui. CODEN: SHJIEG. ISSN:
1000-3770. DOCUMENT TYPE: Journal CA Section: 61 (Water)
The study of purifn. of drinking water contg. phenol for industrial
purpose using activated carbon-chlorine dioxide method (C-ClO2
method) was done. The exptl. results and the process calcn. showed
that both activated carbon and chlorine dioxide have good ability to
remove phenol. The C-ClO2 method for phenol removal has the
advantages of low investment, low cost and high quality of produced
water, as compared to using activated carbon or chlorine dioxide alone
and is an ideal way to remove phenol from drinking water contg.
phenol.
472.
130:103265
Metalorganic CVD of oxide ceramic films.
Hintermaier, Frank (Siemens Aktiengesellschaft, Germany). Eur. Pat.
Appl. EP 892082 A1 20 Jan 1999, 10 pp. DESIGNATED STATES: R:
AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LI, LU, NL, SE, MC, PT, IE,
SI, LT, LV, FI, RO. (German). (European Patent Organization).
CODEN: EPXXDW. CLASS: ICM: C23C016-40. APPLICATION: EP
1998-107568 23 Apr 1998. PRIORITY: DE 1997-19730119 14 Jul
1997. DOCUMENT TYPE: Patent CA Section: 75 (Crystallography
and Liquid Crystals) Section cross-reference(s): 57, 76
In metalorg. CVD of oxide ceramics, esp. SBT and BST, metalorg.
precursors are evapd., an accelerator is introduced to initiate oxidn. of
the precursors, the precursors are oxidized to form metal oxides, and
the metal oxides are deposited.
473.
130:97048
Correlation between chemical, fiber and paper properties of peracid-
and chlorine dioxide-bleached pine and birch kraft pulps by multivariate
analysis.
Seisto, Anu; Poppius-Levlin, Kristina; Fuhrmann, Agneta (Finland).
Pap. Puu, 80(7), 520-528 (English) 1998 Suomen Paperi- ja
Puutavaralehti Oy. CODEN: PAPUAU. ISSN: 0031-1243.
DOCUMENT TYPE: Journal CA Section: 43 (Cellulose, Lignin, Paper,
and Other Wood Products)
Birch and pine kraft pulps were bleached with sequences contg.
peracetic acid, Caro's acid, or ClO2. The chem., fiber, and paper
properties of the pulps were detd. after each bleaching stage in order
to find out in which stage differences between the pulps appear.
Correlations between the pulps and pulp properties were studied using
multivariate anal. (Principal Component Anal. (PCA)). According to the
results, the bonding and strength properties of unbeaten ECF bleached
pulps were higher than those of TCF bleached pulps. The TCF pine
pulps were very similar to each other, whereas the TCFPfa birch pulp
differed from the others in having lower strength. The TCFPfa pulps also
had lower surface lignin contents than the other pulps. In both pine and
birch pulps, higher paper strength properties could be obtained with
high carboxyl group content, but the carboxyl group content alone could
not explain the differences between the pulps. On the other hand, the
ECF pulps had both longer fibers and less fiber deformations, which
could partly explain their higher strength. Viscosity was a good
indication of the strength properties in the case of birch pulps. After
beating for 2000 revs in a PFI mill, the strength properties of the TCF
pulps were inferior to those of the ECF pulp. In the case of pine, this
was probably caused by the higher zero-span strength and the better
bonding properties of the ECF fibers, whereas the difference between
the birch pulps was mainly in the bonding properties. Bleaching to 85%
brightness instead of 89% by using less peracid in bleaching brought
the strength properties closer to those of the ECF pulp, but the same
level could not be reached.
474.
130:97045
Role of oxygen in the preliminary stage of bleaching of bamboo +
eucalyptus (70:30) pulp followed by multi-stage bleaching sequences.
Mishra, B. P.; Sharma, G. D.; Bhargava, G. G. (Research Division,
Orient Paper Mills, Amlai Paper Mills 484 117, India). IPPTA, 10(1),
1-12 (English) 1998 Indian Pulp and Paper Technical Association.
CODEN: IPPTDO. ISSN: 0379-5462. DOCUMENT TYPE: Journal CA
Section: 43 (Cellulose, Lignin, Paper, and Other Wood Products)
Section cross-reference(s): 60
Kraft digestions of bamboo + eucalyptus (70:30) were performed in
order to get higher kappa no. (29.5) and lower kappa no. (25.2) pulps,
and the pulps were bleached under O/C/E/H sequence to achieve
79-80% P.V. brightness. Effluents after each bleaching stage were
studied. Unbleached pulp, alkali/oxygen, C/E/H, and O/C/E/H
sequence bleached pulps were evaluated for their phys. strength
properties. In order to go for still higher brightness (84-85% PV) and
retaining good phys. strength properties, the lower kappa no. (25.2)
bamboo + eucalyptus (70:30) unbleached pulp was bleached under
O/C/EP/H, O/C/EP/H/P, O/C/EP/H/D sequences. The effluent
characteristics at each stage of bleaching and phys. strength
properties of the finally bleached pulp were evaluated. It was obsd. that
lower kappa no. (25.2) pulp bleached under O/C/E/H sequence gives
higher phys. strength properties and reduces pollution parameters
considerably, compared to higher kappa no. (29.5) pulp bleached
under similar bleaching sequence. To get higher strength properties
and higher brightness (84-85% PV), hydrogen peroxide and chlorine
dioxide were used in O/C/EP/H, O/C/EP/H/P and O/C/EP/H/D
sequences. Bleached pulp under O/C/EP/H/D sequence gives higher
viscosity and phys. strength properties followed by O/C/EP/H/P and
O/C/EP/H sequences. AOX calcd. theor. gives an idea that the limit of
total chlorine 2 Kg/ton of pulp could be achieved by incorporating
alkali/oxygen delignification stage prior to C/E/H, C/EP/H/P, and
C/EP/H/D sequences and afterwards installing A.S.P. or aeration
system at the effluent treatment plant.
475.
130:86363
Accurate ab initio near-equilibrium potential energy and dipole moment
functions of the X 2B1 and first excited 2A2 electronic states of OClO
and OBrO.
Peterson, Kirk A. (Department of Chemistry, Washington State
University, 2710 University Drive, Richland, WA 99352, USA). J.
Chem. Phys., 109(20), 8864-8875 (English) 1998 American Institute of
Physics. CODEN: JCPSA6. ISSN: 0021-9606. DOCUMENT TYPE:
Journal CA Section: 65 (General Physical Chemistry) Section
cross-reference(s): 73
Using highly correlated multireference CI wave functions with large
correlation consistent basis sets, three-dimensional near-equil.
potential energy functions (PEFs) have been calcd. for the X 2B1 and
first excited 2A2 electronic states of the atmospherically important OClO
and OBrO radicals. The anal. PEFs have been used in perturbational
and variational calcns. of the anharmonic spectroscopic consts. and
vibrational spectra of both species. Excellent agreement with the
available exptl. data are obsd. for both species and electronic states,
e.g., the vibrational fundamental frequencies in the ground electronic
states are reproduced to within about 5 cm-1. For the A 2A2 state of
OClO, it is demonstrated that the anomalously strong intensity of the n3
mode in the UV absorption spectrum is due to strong anharmonic
coupling between the stretching vibrations and not to a double min. in
the potential. Three-dimensional elec. dipole moment functions have
also been calcd. for the ground electronic states of both species.
These were used to calc. accurate abs. IR absorption intensities for the
fundamentals and low-lying overtones and combination bands of both
species.
476.
130:83717
Energetics of ammonium perchlorate decomposition steps.
Politzer, Peter; Lane, Pat (Dep. Chem., Univ. New Orleans, New
Orleans, LA 70148, USA). THEOCHEM, 454(2-3), 229-235 (English)
1998 Elsevier Science B.V. CODEN: THEODJ. ISSN: 0166-1280.
DOCUMENT TYPE: Journal CA Section: 50 (Propellants and
Explosives)
Energy min. and enthalpies at 298 and 800 K were computed for 37
atoms, mols. and ions that have been implicated as intermediates in
the thermal decompn. of ammonium perchlorate. These data permit
the calcn. of DH(298 K) and DH(800 K) for hundreds of reactions that
may be involved; 39 of these are listed, and several possible decompn.
pathways are outlined. The computations were carried out at the d.
functional B3PW91/6-3ll+G(2df) level, which we found to be effective for
systems contg. several oxygen and/or chlorine atoms in close proximity.
The DH(298 K) and DH(800 K) are found to differ by less than 1.0 kcal
mol-1. We have identified an intermediate complex in the sublimation
of ammonium perchlorate (believed to be the first decompn. step)
which accounts for the activation energy of sublimation being
considerably less than its overall enthalpy change.
477.
130:83666
New process in preparation of stable chlorine dioxide.
Cui, Guanghua; Sun, Xiaolan (Chemical Engineering Department,
Hebei Inst. of Technology, Tangshan, Peop. Rep. China). Hebei
Ligong Xueyuan Xuebao, 20(4), 71-73 (Chinese) 1998 Hebei Ligong
Xueyuan Xuebao Bianjibu. CODEN: HLXUFU. ISSN: 1007-2829.
DOCUMENT TYPE: Journal CA Section: 49 (Industrial Inorganic
Chemicals)
The article introduces a new process for prepn. of stable chlorine
dioxide by reducing sodium chlorate in acidic aq. soln. with oxalic acid.
478.
130:83081
Process for manufacturing bleached pulp including recycling.
Maples, Gerald E.; Caron, Joseph R.; Fleck, John A. (Champion
International Corporation, USA). U.S. US 5853535 A 29 Dec 1998, 24
pp., Cont.-in-part of U.S. Ser. No. 224,690. (English). (United States of
America). CODEN: USXXAM. CLASS: ICM: D21C011-04. ICS:
D21C011-10. NCL: 162030100. APPLICATION: US 94-335099 7
Nov 1994. PRIORITY: US 91-646179 28 Jan 1991; US 92-873673 24
Apr 1992; US 92-944327 14 Sep 1992; US 94-224690 8 Apr 1994.
DOCUMENT TYPE: Patent CA Section: 43 (Cellulose, Lignin, Paper,
and Other Wood Products)
Bleaching wood pulp comprises subjecting the wood pulp, after brown
stock washing, to an O delignification stage, a washing sequence, a
first Cl dioxide bleaching stage, an oxidative extn. stage, optionally *1
final Cl dioxide bleaching stage and then recycling the filtrate from the
oxidative extn. stage counter-currently through the bleaching plant and
brown stock washing. Addnl., and quite beneficially, the filtrate from the
first Cl dioxide bleaching stage is also recycled counter-currently
through the brown stock washing, significantly reducing the
environmental impact assocd. with the manuf. of bleach wood pulp.
479.
130:75755
Cysticidal effect of chlorine dioxide on Giardia intestinalis cysts.
Winiecka-Krusnell, Jadwiga; Linder, Ewert (Microbiology and Tumour
Biology Centre, Swedish Institute for Infectious Disease Control and
Department of Clinical Parasitology, Karolinska Institute, Stockholm
S-105 21, Swed.). Acta Trop., 70(3), 369-372 (English) 1998 Elsevier
Science B.V. CODEN: ACTRAQ. ISSN: 0001-706X. DOCUMENT
TYPE: Journal CA Section: 1 (Pharmacology)
The authors report on the effects of chlorine dioxide on the viability of
Giardia intestinalis cysts. Samples contg. 1 x 103 cysts/mL were
suspended in Aqua Care dild. to a final concn. of 1 mg ClO2/l and
incubated for different times at room temp. This concn. caused
inactivation of approx. 60% of viable cysts in 1 min. However,
prolonged exposure time and increased ClO2 concn. proved to be
more effective. Control of Giardia in drinking water aims at 99.99%
removal/inactivation of the parasite. After overnight incubation in 1 mg/l
of disinfectant, 97.7% of viable cysts were inactivated, which is close to
the range recommended by the US Environmental Protection Agency.
480.
130:68707
Manufacture of chlorine dioxide by activating an impregnated zeolite
crystal mixture.
Klatte, Fred (USA ). U.S. US 5853689 A 29 Dec 1998,12 pp.,
Cont.-in-part of U.S. Ser. No. 798,873. (English). (United States of
America). CODEN: USXXAM. CLASS: ICM: C01B011-02. NCL:
423478000. APPLICATION: US 1998-89611 3 Jun 1998. PRIORITY:
US 1997-798873 11 Feb 1997. DOCUMENT TYPE: Patent CA
Section: 49 (Industrial Inorganic Chemicals)
A method for producing chlorine dioxide comprises activating a mixt. of
impregnated zeolite crystals and regenerating the mixt. after chlorine
dioxide prodn. The activation is accomplished by causing water or a
moisture-contg. gas (e.g., air including water vapor) to flow through the
mixt. or otherwise exposing the mixt. to such fluid, or by exposing the
mixt. to liq. hydrogen peroxide, liq. sulfuric acid, ferric chloride soln., or
sodium chlorate soln. The mixt. can include sodium
chlorite-impregnated zeolite crystals and zeolite crystals impregnated
with ferric chloride, ferric sulfate, or both, and optionally also zeolite
crystals impregnated with calcium chloride. Alternatively, the mixt.
includes sodium chlorate-impregnated zeolite crystals, sulfuric
acid-impregnated zeolite crystals, zeolite crystals impregnated with one
or more of calcium chloride (or another deliquescent or water
absorbing and retaining substance, such as one or more of ferric
chloride and ferric sulfate), and an oxidizer (such as hydrogen peroxide,
sodium metabisulfite, or sodium bisulfite). The oxidizer reacts (in the
presence of water absorbed by the deliquescent or water absorbing
substance) to release another substance which in turn reacts with one
or more of the other impregnating substances to produce chlorine
dioxide. The chlorine dioxide release rate can be controlled in any of
several ways, including by selecting the concn. and amt. of activating
liq., or using zeolite having a selected wt. ratio of one or more
impregnating substance to zeolite.
481.
130:68693
Manufacture of chlorine dioxide.
Cowley, Gerald; Lipsztajn, Marek (Sterling Canada, Inc., USA). U.S.
US 5851374 A 22 Dec 1998, 5 pp. (English). (United States of
America). CODEN: USXXAM. CLASS: ICM: C01B011-02. NCL:
205471000. APPLICATION: US 97-781045 9 Jan 1997.
DOCUMENT TYPE: Patent CA Section: 49 (Industrial Inorganic
Chemicals)
Chlorine dioxide is produced by reaction of chlorate ions, usually
provided by sodium chlorate, with a persulfate in an aq. acid reaction
medium contg. sulfuric acid. Byproduct sodium sulfate, sulfuric acid
feedstock or mixt. may be electrolyzed to form the persulfate for the
reaction.
482.
130:60362
Device for determination of chlorine dioxide concentration.
Ogawa, Katsutoshi; Shimizu, Takashige (Chisso Corp., Japan). Jpn.
Kokai Tokkyo Koho JP 10311790 A2 24 Nov 1998 Heisei, 7 pp.
(Japanese). (Japan). CODEN: JKXXAF. CLASS: ICM: G01N021-27.
APPLICATION: JP 97-134517 9 May 1997. DOCUMENT TYPE:
Patent CA Section: 79 (Inorganic Analytical Chemistry) Section
cross-reference(s): 73
The title device is used for easily detn. of ClO2 concn. in gas or liq.
samples. The device comprises a flow cell, a sample supplier, a light
source, an electro-optical signal converter, and a signal amplifier. The
sample is continuously supplied into the flow cell which is under irradn.
of a light of 270-500 nm and ClO2 concn. in the range of 0.05-300
mL/m3 is detd. A ClO2 remover is disposed at the outlet of the flow
system.
483.
130:56323
Industrial hygiene aspects of a sampling survey at a bleached-kraft pulp
mill in British Columbia.
Astrakianakis, George; Svirchev, Laurence; Tang, Clement; Janssen,
Robert; Anderson, Judith; Band, Pierre; Le, Nhu; Fang, Raymond; Bert,
Joel (Cancer Control Research, British Columbia Cancer Agency,
Vancouver, BC V5Z 4E6, Can.). Am. Ind. Hyg. Assoc. J., 59(10),
694-705 (English) 1998 American Industrial Hygiene Association.
CODEN: AIHAAP. ISSN: 0002-8894. DOCUMENT TYPE: Journal CA
Section: 59 (Air Pollution and Industrial Hygiene) Section
cross-reference(s): 43
To validate exposure ests. used to investigate correlations between
exposure and cancer risk, 1678 personal measurements were
collected for 46 job titles during 73 day shifts at a bleached-kraft pulp
mill. Measurements included shift-long av. and short-term exposures to
carbon monoxide, chlorine dioxide (ClO2), and hydrogen sulfide; and
shift-long av. exposures to calcium oxide and wood dust (WD). Overall
results indicate low levels of exposure with a few noteworthy
exceptions. Although ClO2 was the exclusive bleaching agent, 77 area
samples indicated that chlorine (Cl2), not ClO2 was present in all areas
apart from the chem. prepn. area (chem-prep) and during a pulp spill.
The highest shift-long exposures to Cl2 were measured in the chip yard
and are attributed to uncontrolled stack emissions. Finally, WD
samples collected from several laborers significantly exceeded
regulatory limits, with the highest exposures measured in the steam and
recovery area. For short-term exposures to ClO2 in chem-prep, 12 of
17 data-logging electro-chem. sensor sample results showed at least
one peak that exceeded the short-term exposure limit of 0.3 ppm. The
use of data-logging equipment quantified short-term exposures that
previously had been characterized only anecdotally. The peaks were
correlated with tasks and upset conditions and, given their transient
nature, these exceedances could not have been detected using
shift-long av.-based sampling devices. Since the respiratory effects of
significant short-term exposures to irritant gases such as Cl2 and ClO2
are well-documented, data-logging instruments are necessary to
characterize exposures in the pulp and paper industry.
484.
130:53871
Multistage bleaching of chemical cellulose pulp.
Nishimura, Takaaki; Misu, Koichi; Iwasaki, Makoto (Oji Paper Co., Ltd.,
Japan). Jpn. Kokai Tokkyo Koho JP 10317291 A2 2 Dec 1998
Heisei, 8 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS: ICM:
D21C009-14. ICS: D21C009-12; D21C009-147. APPLICATION: JP
97-137952 14 May 1997. DOCUMENT TYPE: Patent CA Section: 43
(Cellulose, Lignin, Paper, and Other Wood Products)
The bleaching is began with O delignification then followed by a
3-steps sequence comprising (A) chlorination, (B) O-alkali extn. and
(C) ClO2 oxidn. where the C stage is split in 2 steps and done by
adding alkali to ensure a final pH of 4.5-5.5 for improving delignification
efficiency.
485.
130:53834
Characterization of organic deposits produced in the kraft pulping of
Eucalyptus globulus wood.
del Rio, Jose C.; Gutierrez, Ana; Gonzalez-Vila, Francisco J.; Martin,
Francisco; Romero, Javier (Consejo Superior de Investigaciones
Cientificas, Instituto de Recursos Naturales y Agrobiologia de Sevilla,
Seville E-41080, Spain). J. Chromatogr., A, 823(1 + 2), 457-465
(English) 1998 Elsevier Science B.V. CODEN: JCRAEY. ISSN:
0021-9673. DOCUMENT TYPE: Journal CA Section: 43 (Cellulose,
Lignin, Paper, and Other Wood Products) Section cross-reference(s):
80
The compn. of the org. deposits (the so-called pitch deposits)
accumulated in different parts of the mills during the kraft pulping of
Eucalyptus globulus wood using an ECF (elementary chlorine free)
bleaching sequence has been studied. Three pitch deposits were
selected in the bleaching sequence. The first one was taken just after
the kraft pulping and the oxygen prebleaching step, while the other two
were taken from different parts of the mill after the chlorine dioxide
bleaching step. The pitch deposits were Soxhlet extd. with acetone,
and the exts. were redissolved in chloroform and subsequently
analyzed by gas chromatog. (GC) and gas chromatog.-mass
spectrometry (GC-MS). The compn. of E. globulus wood extractives
was also analyzed for comparison. High temp. short capillary columns
were used for the GC and GC-MS analyses, which enabled the elution
and sepn. of compds. with a wide range of mol. mass, with no prior
derivatization nor fractionation. Sterols and sterol esters were major
compds. in the lipidic extractives of E. globulus wood, and hence,
contribute to pitch deposition during pulping. The compn. of the pitch
deposits varied along the bleaching sequence. The kraft cooking and
oxygen prebleaching had a minor influence on the compn. of the ext. of
the pitch deposits. These exts. were very similar to those of E. globulus
wood extractives, but with a higher content of waxes. No structural
changes of sterols and sterol esters were obsd. In contrast, after
chlorine dioxide bleaching (ECF), the deposits were composed of
satd. sterols and sterol esters, with the remarkable absence of unsatd.
sterols and sterol esters, mainly the b-sitosterol and b-sitosterol esters,
which were completely degraded. The insol. residues left after acetone
extn. of the pitch deposits were analyzed by Curie-point flash
pyrolysis-GC-MS and by pyrolysis-methylation-GC-MS. Whereas
conventional pyrolysis released series of n-alkanes/n-alkenes, a series
of fatty acid Me esters were released after pyrolysis-methylation,
suggesting that the residues left after acetone extn. might be made up
of fatty acids salts. Very minor amts. of ellagic acid were also found in
all the pitch deposits, probably deposited as magnesium complex.
486.
130:42410
The possible detection of OBrO in the stratosphere.
Renard, Jean-Baptiste; Pirre, Michel; Robert, Claude; Huguenin, Daniel
(Laboratoire de Physique et Chimie de l'Environnement / CNRS,
Orleans, Fr.). J. Geophys. Res., [Atmos.], 103(D19), 25383-25395
(English) 1998 American Geophysical Union. CODEN: JGRDE3.
ISSN: 0148-0227. DOCUMENT TYPE: Journal CA Section: 59 (Air
Pollution and Industrial Hygiene) Section cross-reference(s): 53
The anal. of spectral residua recorded at night by the balloon-borne
AMON (Absorption par Minoritaires Ozone et NOx) UV-visible
spectrometer during 5 stratospheric flights at middle and high latitudes
showed that some absorption features remain in the 475-550 nm
range, while the Rayleigh, aerosol, O3, and NO2 contributions are
subtracted. Data redn. relating to these spectral lines are presented for
the flight of Feb. 26, 1997, at Kiruna, Sweden, inside the polar vortex.
A good agreement exists between these unknown absorption features
and those attributed to OBrO during recent lab. measurements.
Measurement results from the other AMON flights are also presented.
Assuming a OBrO cross section max. similar to that of OClO, an upper
limit for the OBrO mixing ratio was obsd. around 20 pptv at
mid-latitude, implying that OBrO would be the principal Br species at
night in the middle stratosphere. At high latitude, the OBrO mixing ratio
decreases, particularly in the presence of OClO (also measured by
AMON). Results are contradictory to current knowledge and, if
confirmed, could argue for major revision of the assumed Br chem. in
the stratosphere.
487.
130:42356
Retrospective exposure assessment with emission inventories. A new
approach to an old problem.
Argo, James (IntrAmericas Center for Environment and Health Inc.,
Wolfe Island, ON K0H 2Y0, Can.). Environmetrics, 9(5), 505-518
(English) 1998 John Wiley & Sons Ltd. CODEN: ENVCEE. ISSN:
1180-4009. DOCUMENT TYPE: Journal CA Section: 59 (Air Pollution
and Industrial Hygiene) Section cross-reference(s): 4, 61
A procedure to est. chem. exposure retrospectively for the purpose of
studying individual chronic chem. exposure is described: the unique
combination of a case-control study design which eliminates diln. by
mobility, coupled with an emission inventory to est. exposure nationally
for up to 35 yr latency, is used. The retrospective exposure
assessment (REA) methodol. leads to an Exposure Index (EI) to
describe the av. historic exposure at a point. The approach is
demonstrated with an est. of the av. chem. environment in each of 78
pulp-producing communities in Canada in 1980, considering
process-related emissions. A procedure to partially validate the
pollution est. and the est. of toxicity is shown.
488.
130:29799
Quantitative description of the chloride effect on chlorine dioxide
generation from the ClO2--HOCl reaction.
Yin, Guohong; Ni, Yonghao (Dr. Jack McKenzie Limerick Pulp and
Paper Research and Education Centre, University of New Brunswick,
Fredericton, NB E3B 6C2, Can.). Can. J. Chem. Eng., 76(5), 921-926
(English) 1998 Canadian Society for Chemical Engineering. CODEN:
CJCEA7. ISSN: 0008-4034. DOCUMENT TYPE: Journal CA Section:
67 (Catalysis, Reaction Kinetics, and Inorganic Reaction Mechanisms)
The generation of chlorine dioxide from the reaction between
hypochlorous acid and chlorite with or without an initial chloride addn.
has been studied under slightly acidic conditions. Chloride (Cl-), one of
the products from the reaction, not only changes the reaction
stoichiometry, but also alters the rate law. It was found that the
formation of chlorine dioxide from the HOCl-ClO2- system consists of
two distinct parts, one is promoted by chloride, the other is independent
of chloride. The overall kinetics of the chlorine dioxide generation from
the reaction is: d[ClO2]/dt = {k1 + k2[Cl-]} [ClO2-][HOCl][H+]. This model
can very well predict the reaction under the following conditions:
273-303K, [ClO2-] = 0.001-0.00267 mol/L, [ClO2-]/[HOCl] = 2, and pH
3.86-4.91.
489.
130:28676
Accidental releases analysis for toxic aqueous solutions.
Sung, Hung-Ming (Trinity Consultants, Dallas, TX 75243, USA). Proc.,
Annu. Meet. - Air Waste Manage. Assoc., 91st,
TP50A05/1-TP50A05/8 (English) 1998 Air & Waste Management
Association. CODEN: PAMEE5. ISSN: 1052-6102. DOCUMENT
TYPE: Journal; (computer optical disk) CA Section: 59 (Air Pollution
and Industrial Hygiene) Section cross-reference(s): 43, 60
As a result of the cluster rule for the control of the hazardous air
pollutants, pulp and paper mills are in the process of further substituting
Cl with aq. chlorine dioxide for their bleaching operations. In addn.,
ammonia aq. solns. are applied by paper mills in various processes.
An evapn. model including both heat and mass transfer for aq. solns.
has been developed to quantify chem. evapn. rates. Chem. and phys.
properties for chlorine dioxide and ammonia aq. solns. have been
analyzed to allow plants to perform a dynamic anal. for various
accidental release scenarios. This paper provides a discussion of the
methodologies for quantifying source parameters and modeling
downwind concns. from liq. spills of chlorine dioxide and ammonia aq.
solns.
490.
130:21736
Sustained-release biocidal powders.
Wellinghoff, Stephen T.; Barenberg, Summer A.; Dixon, Hong; Kampa,
Joel J. (Bernard Technologies, Inc.; Southwest Research Institute,
USA). PCT Int. Appl. WO 9852413 A1 26 Nov 1998, 50 pp.
DESIGNATED STATES: W: AU, JP, SG; RW: AT, BE, CH, CY, DE,
DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE. (English). (World
Intellectual Property Organization). CODEN: PIXXD2. CLASS: ICM:
A01N025-12. ICS: A01N025-14; A01N025-22; A01N025-26;
A61K009-14; A61K009-16; A61K009-50. APPLICATION: WO
98-US7991 22 Apr 1998. PRIORITY: US 97-858859 19 May 1997.
DOCUMENT TYPE: Patent CA Section: 5 (Agrochemical
Bioregulators) Section cross-reference(s): 63
A powder for sustained release of a gas includes a hydrophilic core, a
hydrophobic layer on an outer surface of the hydrophilic core, and
particles in contact with the hydrophobic layer. The hydrophobic layer
contains an acid-releasing agent. The particles contain an anhyd.
material capable of binding with water. The core, the particles, and the
hydrophobic layer are free of water, and the core is capable of
generating and releasing a gas after hydrolysis of the acid-releasing
agent. The gases are ClO2, SO2, H2S, HCN, NO2, NO, Cl2O and Cl.
491.
130:19792
ESR study of the structure of intercalation compounds of fluorinated
graphite and processes occurring therein using NO2 and ClO2 radicals
as spin probes.
Nadolinnyi, V. A.; Makotchenko, V. G.; Danilenko, A. M. (Institute of
Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences,
Russia). J. Struct. Chem., 39(2), 204-211 (English) 1998 Consultants
Bureau. CODEN: JSTCAM. ISSN: 0022-4766. DOCUMENT TYPE:
Journal CA Section: 77 (Magnetic Phenomena) Section
cross-reference(s): 67
For intercalation compds. of fluorinated graphite at 77-300 K, the
parameters of the spin Hamiltonian are detd. from the angular
dependence of the ESR spectra, the NO2 and ClO2 radicals are
located, and their mobility at low temps. was studied. At 77-200 K,
vibrational and rotational motions around the O-O axis are defreezed.
This is attributed to donor-acceptor interactions between the neg.
charged O atoms of NO2 and ClO2 radicals and the pos. charged C
atoms of fluorinated graphite. The calcd. activation energies (0.35
kcal/mol for ClO2 and 0.6 kcal/mol for NO2) for defreezing the
rotational-vibrational motions of these two radicals are close. Using
NO2 radicals as spin probes allowed the authors to find two types of
regions in ICFG, which differ in the rate of NO2 diffusion. These regions
probably are the filled and unfilled parts of graphite fluoride layers. It is
attempted to explain the low pressure of the satd. vapor of the
intercalate over ICFG by the presence of unfilled layers near the
boundaries of ICFG flakes.
492.
130:15088
Method of minimizing scaling problems in manufacture of bleached
cellulose pulp while using an essentially fully closed washing liquid flow
pattern.
Liden, Jan Georg; Magnusson, Staffan Lars Sune (Mo Och Domsjo
Aktiebolag, Swed.). PCT Int. Appl. WO 9851855 A1 19 Nov 1998, 32
pp. DESIGNATED STATES: W: AU, BR, CA, JP, NO, NZ, US; RW:
AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT,
SE. (English). (World Intellectual Property Organization). CODEN:
PIXXD2. CLASS: ICM: D21C009-10. ICS: D21C011-00.
APPLICATION: WO 98-SE879 12 May 1998. PRIORITY: SE 97-1778
14 May 1997. DOCUMENT TYPE: Patent CA Section: 43 (Cellulose,
Lignin, Paper, and Other Wood Products)
Scaling problems in, for instance, washing app. occur when using fully
closed liq. flow patterns in the manuf. of bleached cellulose pulp. A
soln. to this problem, and relates to a method for minimizing calcium
caused scaling problems when washing and/or increasing the
consistency of cellulose pulp suspensions and in other cellulose pulp
suspension processes where the pulp suspension is treated in *2
stages, including *1 bleaching stage, alternately in a neutral/acidic and
alk. environment, wherein washing liq. (suspension liq.) is passed
counter-currently such that the treatment process will be essentially fully
closed with respect to the washing liq. (suspension liq.) flow pattern,
characterized in that the major part of the calcium present in and on
cellulose pulp fibers incoming to the treatment process is prevented
from being released in the suspension liq., by adding a water-sol.,
oxalate-contg. chem. to the suspension liq. downstream of the
neutral/acidic treatment stage and/or to the pulp suspension
immediately prior to or in the neutral/acidic treatment stage.
493.
130:15073
Ethanol-based chlorine dioxide bleaching and extraction.
Brogdon, Brian N.; Dimmel, Donald R.; McDonough, Thomas J.
(Institute of Paper Science and Technology, Atlanta, GA 30318, USA).
Adv. Lignocellul. Chem. Ecol. Friendly Pulping Bleaching Technol., Eur.
Workshop Lignocellul. Pulp, 5th, 567-570. University of Aveiro: Aveiro,
Port. (English) 1998. CODEN: 66TZAG. DOCUMENT TYPE:
Conference CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood
Products)
Research has been conducted to det. whether an ethanol-water
medium could improve the removal of residual lignin from an
unbleached softwood kraft pulp during ClO2 (D) bleaching. A
90%-ethanol D0-stage yielded pulps with the same residual lignin
content as an aq. D0-stage. Lignin removal was strongly inhibited when
high amts. of ethanol were used in a subsequent alk. extn. (E) stage.
The effect was attributed to a low soly. of ionized lignin in ethanol, rather
than to differing degrees of lignin entrapment caused by fiber
de-swelling. An acidic ethanol extn. (AE) stage at elevated temps. was
effective at removing residual lignin in the D0-pulp; however, the
resulting pulp was more difficult to bleach than aq. DE treated pulp in a
subsequent aq. D1-stage. Overall, the use of an ethanol medium for a
ClO2 delignification does not hinder delignification or subsequent aq.
bleaching stages; however, ethanol hinders E-stage delignification.
494.
130:15071
Bleaching softwood kraft pulp: the role of certain common chemical
elements in the first alkali (E) and the following chlorine dioxide stage
(D1) of ECF bleaching.
Dahl, O.; Niinimaki, J.; Ammala, A.; Kuopanportti, H. (Department of
Process Engineering, University of Oulu, Oulu 90570, Finland). Adv.
Lignocellul. Chem. Ecol. Friendly Pulping Bleaching Technol., Eur.
Workshop Lignocellul. Pulp, 5th, 517-521. University of Aveiro: Aveiro,
Port. (English) 1998. CODEN: 66TZAG. DOCUMENT TYPE:
Conference CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood
Products) Section cross-reference(s): 60
The effects of certain metal ions and silicate anion in process water in
the first alkali stage and the following chlorine dioxide stage on reagent
consumption and various pulp properties were studied. A closed water
circulation system was simulated by increasing the ions concn. only in
the first alkali (E1) stage. The results indicate that iron ions added to
process water clearly decreased brightness both in the E1 and the
following D1 stage, being dose-dependent, while only substantial amts.
of added copper or manganese ions (>50 mg/l) decreased brightness
in the E1 stage. An addn. of iron, manganese or copper ions into the
E1 stage, however, had no real effect on other measured pulp
properties or reagent consumption in the E1 stage and the following D1
stage. An addn. of magnesium ions into the E1 stage decreased pulp
brightness after the E1 stage, but also hindered viscosity loss in the
following D1 stage. An addn. of calcium ions into the E1 stage had a
slight neg. impact on pulp properties and reagent consumption in both
stages, while potassium and silicate ions behaved like inert materials
in the bleaching tests.
495.
130:15039
Study on residual lignin structure and extractives in eucalyptus kraft
pulps with different bleachabilities.
Evtuguin, D. V.; Paulino, P. D.; Neto, C. Pascoal; Carvalho, A. P.
(Department of Chemistry, University of Aveiro, Aveiro 3810, Port.).
Adv. Lignocellul. Chem. Ecol. Friendly Pulping Bleaching Technol., Eur.
Workshop Lignocellul. Pulp, 5th, 401-404. University of Aveiro: Aveiro,
Port. (English) 1998. CODEN: 66TZAG. DOCUMENT TYPE:
Conference CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood
Products)
Eucalyptus kraft pulps with similar residual lignin content expressed as
kappa no., cooked using different alkali and temp. profiles, showed
different bleachabilities by DEDED sequence. The residual lignins
isolated from these pulps by acidolysis technique were characterized
using methods of wet chem. and 1H NMR. No clear correspondence
was found between the principal residual lignin structural features
(abundance of the lignin interunit linkages, condensation degree, etc.)
in pulps and their bleachability. The quantification of extractives sol. in
methanol-water (1:1) soln. and dichloromethane in unbleached pulps
gave values comparable to those of residual lignins contents, indicating
on a possible substantial contribution of extractive compds. for chlorine
dioxide consumption in DEDED bleaching.
496.
130:7466
Compositions and methods for enhancing contact lens wearability.
Vehige, Joseph G.; Currie, James P. (Allergan Sales, Inc., USA). PCT
Int. Appl. WO 9850084 A1 12 Nov 1998, 35 pp. DESIGNATED
STATES: W: AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN,
CU, CZ, DE, DK, EE, ES, FI, GB, GE, GH, GM, GW, HU, ID, IL, IS, JP,
KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN,
MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM,
TR, TT, UA, UG, UZ, VN, YU, ZW, AM, AZ, BY, KG, KZ, MD, RU, TJ,
TM; RW: AT, BE, BF, BJ, CF, CG, CH, CI, CM, CY, DE, DK, ES, FI,
FR, GA, GB, GR, IE, IT, LU, MC, ML, MR, NE, NL, PT, SE, SN, TD, TG.
(English). (World Intellectual Property Organization). CODEN:
PIXXD2. CLASS: ICM: A61L002-18. APPLICATION: WO 98-US7826
15 Apr 1998. PRIORITY: US 97-854221 9 May 1997. DOCUMENT
TYPE: Patent CA Section: 63 (Pharmaceuticals)
Compns. and methods for treating a contact lens very effectively and
conveniently provide enhanced contact lens wearability by reducing the
actual or perceived ocular sensitivity which results from exposing a
contact lens to non-oxidative antimicrobial components. The present
system takes advantage of inactivating or deactivating a non-oxidative
antimicrobial component located on or in a contact lens to reduce the
ocular sensitivity caused by placing the lens in the eye. A lens is
disinfected with ReNu and then rinsed in isotonic soln. contg. Na
CM-cellulose which interacts with the biguanide from ReNu.
497.
130:5016
Correlating 31P NMR and fluorescence data of residual kraft lignins by
multivariate chemometric analysis.
Billa, Evaggeli; Argyropoulos, Dimitris S.; Koukios, Emmanuel G.
(Bioresource Technology Unit, Department of Chemical Engineering,
National Technical University of Athens, Athens GR-15700, Greece).
Adv. Lignocellul. Chem. Ecol. Friendly Pulping Bleaching Technol., Eur.
Workshop Lignocellul. Pulp, 5th, 183-186. University of Aveiro: Aveiro,
Port. (English) 1998. CODEN: 66TZAG. DOCUMENT TYPE:
Conference CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood
Products)
The predictive potential of combining complex sets of spectral data
from fluorescence and quant. 31P NMR spectroscopies using
chemometric tools is assessed. This feasibility study was
accomplished by isolating a softwood residual kraft lignin and treating it
with alk. oxygen, chlorine dioxide, alk. peroxide and dimethyldioxirane,
as a function of oxidant charge, time and temp. Fluorescence data
alone allowed the discrimination of subtle oxidant differences resulting
in the formation of different clusters from the four oxidants used.
Furthermore, the introduction of detailed structural information as it
emerges from quant. 31P NMR permitted the correlation of carboxylic
acids and guaiacyl phenolic moieties with fluorescence intensity for all
oxidants examd. Finally, fluorescence spectroscopic information
derived from whole pulp samples was found to correlate with functional
group information of lignins isolated from the same sheet.
498.
130:3281
Sterilization and washing of fresh foods with solutions containing
chlorine dioxide.
Goto, Fumihiro; Matsubara, Mamoru (Ryubi K. K., Japan). Jpn. Kokai
Tokkyo Koho JP 10313839 A2 2 Dec 1998 Heisei, 9 pp. (Japanese).
(Japan). CODEN: JKXXAF. CLASS: ICM: A23L003-358. ICS:
A23B004-14; A23B007-153. APPLICATION: JP 97-128964 19 May
1997. DOCUMENT TYPE: Patent CA Section: 17 (Food and Feed
Chemistry)
Fresh foods (e.g. vegetables, fruits, meat, and fish) are washed and
sterilized with liqs, contg. aq. ClO2 solns. (preferably at 5-200 ppm as
Cl) and emulsifiers (preferably at 20-1000 ppm). Cut lettuce was
immersed in an aq. soln. contg. 20 ppm ClO2 (Purogene) and 200 ppm
sorbitan fatty acid ester (Emasol Super L 10F) at 15* for 3 min and left
at 25* for 48 h to show total control of Escherichia coli and other
bacteria without discoloration of the cut surfaces.
499.
132:352141
Method and device for treatment of wastewater treatment sludge using
chlorine-containing oxidation agent.
Takechi, Tatsuo; Tsubone, Toshiaki; Miyata, Jun; Baba, Akira;
Utagawa, Satoru; Sawada, Toyoshi; Endo, Shinichi (Nippon Kokan
Co., Ltd., Japan). Jpn. Kokai Tokkyo Koho JP 2000140893 A2 23
May 2000, 10 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS:
ICM: C02F011-06. ICS: C02F011-06; C02F011-12. APPLICATION:
JP 1998-316487 6 Nov 1998. DOCUMENT TYPE: Patent CA Section:
60 (Waste Treatment and Disposal) Section cross-reference(s): 61
The method is carried out by adding Cl-contg. oxidn. agent (e.g.,
sodium hypochlorite) into the sludge-liq. mixt. or its concd. material
from a pptn. pond in biol. wastewater treatment for oxidn. treatment in a
tank, then concn. and dewatering to obtain sepd. liq. from a dewatering
machine, followed by dephosphorization of the liq.
500.
132:349763
Method for generation of chlorine dioxide gas for sterilization.
Inomura, Hisashi; Makino, Yoshinao (Japan ). Jpn. Kokai Tokkyo Koho
JP 2000154003 A2 6 Jun 2000,3 pp. (Japanese). (Japan). CODEN:
JKXXAF. CLASS: ICM: C01B011-02. ICS: A01N001-00;
A01N025-18; A01N059-08. APPLICATION: JP 1998-323134 13 Nov
1998. DOCUMENT TYPE: Patent CA Section: 49 (Industrial Inorganic
Chemicals) Section cross-reference(s): 59, 61
The method is carried out by accommodating stabilized ClO2 (or
NaClO) soln. and acidic powder in container, resp., then mixing the 2
materials for generation of ClO2 gas for disinfection, like coffin.